errors in my computer

Hello my operating system is windows xp and i get all these errors. I have scan with all antivirus and antimalware programs but nothing is found...

This error appears when trying to install Oshi Defender...

http://i59.tinypic.com/34zerec.jpg

This error appears when trying to start game LAst half of darkness the society of the serpent moon... Clicking more information the error is caused by darkvideo.dll...

http://i58.tinypic.com/5v0mfo.jpg

This error appears when trying to run Eset hidden file system reader...

http://i61.tinypic.com/vnfcwp.jpg

This error appears when trying to install Spy Emergency...

http://i62.tinypic.com/xprj12.jpg

This is also when trying to install Spy Emergency...

http://i62.tinypic.com/2prhijn.jpg

This error appears after installing Spy Emergency and then right clicking on some folder or file...

http://i61.tinypic.com/nnvc6p.jpg

And finally this when i have to manually kill explorer.exe and then restart it...

http://i57.tinypic.com/w8kxsy.jpg

Any clues on what might cause these errors? Wrong bios settings? Faulty memory? Missing runtimes? Slow computer?

 

I have scanned with mbam and hitman pro and super antispyware and f-prot and emsisoft and the cleaner and some others and nothing was found.

 

Try to re-install your windows?

 

The first thing to is run sfc/scannow from an elevated command prompt.

If that doesn't fix the issues, run tweaking.com's Windows Repair All-In-One.

If you still have no luck do an inplace upgrade of Windows, which will fix problems with Windows, without you losing any of your installed programs or data.

Edit: I see you're running XP, in which case you need to a repair install instead of inplace upgrade from your Windows CD.